Here's my side mount license plate setup. I think it turned out good. I did it back in July. Zero problems so far.
I started by removing the rear plastic tail like everyone else. The factory wire that powered the oem license plate light is blue. You can see it when you unhook the factory connections when the license plate/plastic tail comes off. I cut my rear plastic so it was level with the bottom of the taillight, just like everyone else. There's plenty of write-ups about the tail procedure. Next support the bottom of the bike cuz you are about to remove the axle. So, remove the exle. When I first slid the mount on the axle and adjusted it into position, the mount hit the welds on the end of the swingarm preventing the plate from being angled to my tastes. I enlarged the axle hole into a slot so I could tilt it back more. You can't make it too much of a slot or you will end up seeing it because the axle head won't cover a big slot, just a smaller one. Tighten all that axle stuff back up. Now for the wiring. I installed my led plate frame and plate and ran the wires between the plate and led frame and angled them towards the swingarm. I don't like the next part- I had nowhere to put the wire so I layed it on top the swingarm and ran it towards the belt guard bolts. Here I ran the wire down and then forward toward the front of the swingarm. I wrapped it around the bottom of the swingarm and back up towards the belt guard again, this time the wire ends up being directly behind the frame and under the driver's seat. You have to be careful here cuz the belt is RIGHT THERE. I drilled two holes in the belt guard so I could run my wire through it to keep the wire off the belt. These holes will be hidden behind the frame. I ran the wire through here going in an upward direction heading towards the battery.
Right next to the battery area is the license plate/tlite/turn sig wiring and it runs along the left frame rail and into the inside of the rear fender and then finally back to the connections. Remember that blue wire I spoke of earlier?? I dug through the wiring loom next to the battery that leads to the rear connections and found that little blue wire. I cut it, crimped a connector on it, and then i connected it to the LED plate wiring I just snaked through half the bike. Crossed my finger and turned the key on. Sweet! It was the same blue wire. The LED's are awesome.
The mount came from road6custom.com vertical side mount bracket for the axle, part number is sku 00043 and its on sale, $24, I think, shipped.
I went to fleabay and bought the plate housing w/built-in led light. It was less than $30.
I realize there are other write-ups on this but I hope my version answers a question for someone sitting on the fence.. Just do it.